Building facade systems are used to cover a building facade including window openings defined in wall portions. The building facade system can include window panels for covering the window openings of the building façade, the window panels being installed on horizontally-extending and vertically-extending mullions encased within the window openings of the building facade.
Various interconnected profiles are provided to frame each window panel and secure said window panel to the mullions of the building facade. To provide both lightness and strength, aluminum is often chosen as an adequate material for the interconnected profiles. However, aluminum and analog metallic materials are good thermal conductors allowing creation of thermal bridges having various paths depending on the configuration of the connection profiles.
Thermal insulation can be therefore provided to reduce thermal flow between the exterior environment and the interior environment (e.g. room of the building). One way to reduce thermal bridges via the connection profiles includes the use of thermal break elements creating a conduction rupture in a metal to metal connection. For example, U.S. Pat. No. 6,442,907 describes a curtain window wall including variations of thermal break elements.
There is still a need for improved thermal insulation reducing thermal flow between the exterior environment and the interior environment of the building façade via the interconnected elements which secure window panels to the mullions.